Please refer to FIG. 1, a conventional paint supplying pail includes a pail body 1 and an upper cover 2. The pail body 1 holds paint inside (not shown in the drawing) and has a paint ejection port 3. The upper cover 2 has an air intake port 4, a regulation valve 5 and a pressure gauge 6. The air intake port 4 can be connected to an air compressor (not shown in the drawing). The air compressor generates high pressure air sent into the pail body 1. The paint ejection port 3 is connected to a spray gun (not shown in the drawing). When the spray gun is opened the high pressure air forces the paint to eject out through the paint ejection port 3 to perform painting operation desired. Such an approach can replace the traditional time-consuming and tedious manual painting operation, hence can reduce operation cost.
When the paint contained in the conventional paint supplying pail is depleted and replenishment is required, users have to unfasten a fastener 7 to remove the upper cover 2 from the pail body 1. It is a tedious and troublesome task. Moreover, when the fastener 7 is wrenched for unfastening the air intake port 4, regulation valve 5 and pressure gauge 6 on the upper cover 2 could be easily impacted by external forces and damaged. In addition, when the high pressure air passes through the air intake port 4 a high speed airflow is generated that could hit the paint held in the pail body 1 and result in spattering the paint to the bottom of the upper cover 2 and cause waste of the paint. In short, the conventional technique still leaves a lot to be desired, such as tedious and troublesome operation of unfastening the upper cover 2 during replenishment of the paint, easy damage of the paint supplying pail and waste of the paint, and cannot fully meet use requirements.